MDM2 antagonist Nutlin-3a potentiates antitumour activity of cytotoxic drugs in sarcoma cell lines.

Background: Frequent failure and severe side effects of current sarcoma therapy warrants new therapeutic approaches. The small-molecule MDM2 antagonist Nutlin-3a activates the p53 pathway and efficiently induces apoptosis in tumours with amplified MDM2 gene and overexpression of MDM2 protein. However, the majority of human sarcomas have normal level of MDM2 and the therapeutic potential of MDM2 antagonists in this group is still unclear.

LSAMP, a novel candidate tumor suppressor gene in human osteosarcomas, identified by array comparative genomic hybridization.

Osteosarcomas are the most common primary malignant tumor of bone, and almost all conventional osteosarcomas are high-grade tumors with complex karyotypes. We have examined DNA copy number changes in 36 osteosarcoma tumors and 20 cell lines using microarray-based comparative genomic hybridization. The most frequent minimal recurrent regions of gain identified in the tumor samples were in 1q21.

Potential for treatment of liposarcomas with the MDM2 antagonist Nutlin-3A.

The MDM2-antagonist Nutlin 3A can efficiently induce apoptosis in osteosarcoma cell lines with amplified MDM2. However, Nutlin-based therapy could be even more important in more common sarcoma types where this aberration is frequent. The well- and de-differentiated liposarcomas have complex marker chromosomes, consistently including multiple copies of the MDM2 locus.